Supinator muscle

Supinator stretch. The supinator muscle runs over the radial nerve, and it can compress that nerve if you do repetitve supination movements (as in turning your palm upwards like when you’re turning a doorknob). Supinator syndrome or radial tunnel syndrome can be mistaken for tennis elbow or lateral epicondylitis, which is a different condition with some similar symptoms such as pain in the outside part of your elbow. See a physical therapist or physician for a proper assessment and diagnosis as

Supinator - Origin, Insertion, Action, 3D Model | AnatomyZone